This invention relates to an improved needle electrode for use with a hypodermic syringe attachment. More particularly the invention relates to a needle electrode for use in electromyography (EMG) in situations wherein it is desired to insert an electrode, in the form of a probe, into a patient to locate a particular muscle and then inject a medicament into that muscle.
Relevant prior art teaches a hypodermic needle with an open lumen, designed for muscle stimulation, muscle motor unit action potential recording, and drug delivery. A physician locates an exact position of the tip of the needle by either recording or stimulating the muscle. Once the physician is satisfied with the location, s/he injects a drug therein via the lumen of the needle. It is known to perform this procedure using a hypodermic needle coated with Teflon (tetra fluoroethylene), except at the cutting faces, in a standard Luer lock hub or connector. A cable with a very rudimentary clip has been supplied for attachment to a square part of the Luer lock connector.
A state-of-the-art search hereon has revealed the following six (6) pertinent prior United States patents:
______________________________________ PATENT NO. DATE INVENTOR(S) ______________________________________ 3,313,293 April 11, 1967 Chesebrough et al. 3,682,162 August 8, 1972 Colyer 4,155,353 May 22, 1979 Rea et al. 4,515,168 May 7, 1985 Chester et al. 4,824,433 April 25, 1989 Marz et al. 4,892,105 January 9, 1990 Prass ______________________________________
Of the foregoing patents, those to Chesebrough et al. and Colyer appear to come closer than any of the others to the present invention.
Chesebrough et al. discloses an electromedical needle having a slender conductive rod with a pointed end and a blunt end. Insulators and conductors are disposed on selected portions of the rod to form a plurality of longitudinal electrodes insulated from each other. A multicontact connector is attached to the blunt end of the rod, and shielded cables connect the contacts of the connectors with the ends of the electrodes closest thereto.
Colyer relates to a combined electrode and hypodermic syringe needle. FIG. 5 of Colyer shows a syringe/electrode which is partly encapsulated in a molded sleeve of sterilizable thermosetting plastic material. The sleeve of Colyer extends over a major portion of hub portions 19 and 24, these being Luer fittings and for about half the length of an outer needle 25. In use the needle is connected with an electronic locator/stimulator and inserted into a patient. By means of well known techniques, location and identification of a sensory nerve or a motor nerve is achieved. A syringe is then attached to the needle and medicament is injected as required.
In order to form the electrical connection in Colyer, some kind of form would have to be provided into which handle material would be cast. The form would then have to be removed, leaving a terminal aperture.
It is an important object of the present invention to provide a needle electrode, for use with a hypodermic syringe attachment, that is of simplified construction.
It is another important object of the invention to provide a needle electrode, for use with a hypodermic syringe attachment, that is easier to use than devices of the prior art.
It is another important object of the invention to provide a needle electrode, for use with a hypodermic syringe attachment, wherein a conductor wire is directly attached to the needle member.
It is another important object of the invention to provide a needle electrode, for use with a hypodermic syringe attachment wherein the hypodermic syringe attachment is directly attached to a handle thus eliminating the Luer fitting that is required in the design of the Colyer device.
It is yet another important object of the invention to provide an improved method of manufacturing a handle member for a needle electrode.
The foregoing and other objects and advantages of the invention will appear more clearly hereinafter.